Cardiotomy reservoir



April 21, 1970 D. J. BENTLEY CARDIOTOMY RESERVOIR Filed Dec. 1, 1967FIGZ FROM

SURGICAL FIELD INVENTOR. DONALD J. BENTLEY W W, M

ATTORNEYS.

United States Patent O 3,507,395 CARDIOTOMY RESERVOIR Donald J. Bentley,Santa Ana, Califl, assignor to Bentley Laboratories, a corporation ofCalifornia Filed Dec. 1, 1967, Ser. No. 687,230 Int. Cl. C02c 1/10 US.Cl. 210-443 5 Claims ABSTRACT OF THE DISCLOSURE Apparatus for reclaimingblood from the surgical field of a patient by drawing blood from thefield to the apparatus and returning the blood directly or indirectly tothe patient, characterized in that the apparatus includes a plate in thepath of incoming blood for spreading the blood into a thin sheet, and afibrous membrane surrounding the plate and interposed in the path ofblood flow outwardly of the apparatus, the combined spreading andfiltering action removing impurities from the blood and placing theblood in a condition for return to a patient.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to apparatuses for reclaiming blood withdrawn from the surgicalfield of a patient and placing the blood in condition for return to thepatient.

Description of the prior art Prior art patents showing related structurefor accomplishing the results for which the structure of this inventionis intended, are the U.S. patents to Collins No. 3,295,297; Everett No.3,191,600; and Desmet No. 2,406,207. Generally speaking, each of thesepatents discloses structure for reclaiming blood drawn from the surgicalfield of a patient and placing it in a condition for return to thepatient or to other apparatus prior to return to the patient. DesmetPatent 2,406,207 relies upon settling of the blood to remove air bubblesor defoam the blood. Collins No. 3,295,297 passes blood through a screenand also across ribbed surfaces to remove air embolisms from the blood.Everett No. 3,191,600 directs the blood against the walls of acollecting chamber so that air bubbles will be removed from the blood asthe blood settles in the bottom of the chamber.

SUMMARY OF THE INVENTION This invention is directed, in brief, to theprovision of an apparatus for reclaiming blood drawn from the surgicalfield of a patient and placing the blood in a condition for return to apatient by removing air bubbles and other foreign matter from the blood.The best mode currently contemplated for carrying out the inventioncomprises a generally spherical member having means, such as a nipple,for connecting the member to a source of negative pressure. Inletnipples lead into a conduit which opens into a plate. The plate issurrounded by a filter material so that incoming blood is first spreadover the plate and then passes through filter material before beingpumped or gravity fed out through an outlet below the plate.

DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of theblood reclaiming apparatus of the present invention;

FIGURE 2 is an enlarged section view taken generally along the line 22of FIGURE 1; and

FIGURE 3 is a fragmentary sectional view taken generally along the line33 of FIGURE 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The blood reclaiming apparatusor reservoir 10 of this invention comprises a spherical ball 12 forminga body or collecting chamber. Preferably the ball is formed by thejuncture of two semi-cylindrical halves 12a and 12b which are suitablyjoined, such as by heat sealing or the like, along flanges 12c and 12d,respectively. The halves 12a and 12b may be made of a clear plastic orother suitable material. A first outlet means or nipple 14 is formed onportion 12a and has a hollow interior 14a which communicates with theinterior 16 of the sphere 12. Nipple 14 may be connected to a rollerpump or to a suitable source of negative pressure, such as a vacuumpump, for reducing the pressure in the interior 16 of the sphere tothereby draw blood from the surgical field of a patient and encourageits flow into the interior of the sphere.

The reservoir 10 is also sometimes used with a positive pressure pumppositioned between the reservoir 10 and the surgical field from whichblood is being withdrawn. In other words, blood is drawn from thesurgical field by the positive pressure pump and then forced into thereservoir 10. In such a use, the nipple 14 may serve as a vent toatmosphere to relieve pressure within the reservoir 10 which may resultfrom the blood being pumped into the reservoir by the positive pressurepump.

The base of sphere portion 12b has anannular opening 18 which issurrounded by depending annular flange 20. A plurality ofcircumferentially spaced inwardly fac ing ribs or indentations 22 areformed in portion 12b adjacent the flange 20. A blood inlet and outletassembly 24 is fitted in the opening 18 defined by flange 20. Thisassembly includes a lower plate 26 having an upwardly extending flange28 of a size and shape to generally matingly engage with the interior ofthe depending flange 20. For positive securement of the assembly 24within the opening 18, the flanges 20 and 28 may be heat sealed orotherwise bonded to each other.

Inlet means in the form of a pair of inlet nipples 30 and 32 divergeoutwardly from lower .plate 26. Each nipple has a hollow interior, suchas 32a, which communicates with the hollow interior or through passage34 of the upstanding cylindrical column 36 integrally formed as part oflower plate 26. Column 36, in turn, supports spreader plate 38 which isa flat disc-like planar surface extending radially about, and slightlybelow the open end 40 of the column 36. A second outlet means or nipple42 depends from lower plate 26 and has a hollow interior or throughpassage 42a which is in communication with the interior 16 of the sphere12.

Filter means or filter element 44 is interposed between the inlet pathof blood and the outlet path therefor by being wrapped about column 36so that it surrounds plate 38 and the open end 40 of column 36. In theillustrated embodiment, this filter element takes the form of apolypropylene filter mesh 46 enclosed within a nylon bag 48. Preferably,filter mesh 46 is coated with a well-known medical silicone anti-foamingmaterial. Bag 48 has tie means 50 at its open end to tie bag 48 andfilter mesh 46 about the column 36 below plate 38 to form asubstantially enclosed chamber 52 about the column 36 and the spreaderplate 38 so that any blood entering through column 36 must pass throughfilter element 44 before returning outwardly of the apparatus by way ofthe outlet nipple 42. Spreader plate 38 serves to hold the filter means44 on column 36 and to spread the interior thereof so as to create thechamber 52 and spread the interior of the filter so that a greatersurface area is exposed for filtering. A radially projecting rib 39extends outwardly from column 3 36. The purpose of ribs 22 and 39 is tohold the filter element 44 spaced from the second outlet means 42 toprevent unintentional sealing of the outlet.

Inlet nipples 30 and 32 are connected to suitable conduit means, such asflexible rubber or plastic tubing 56 and 58, respectively, which leadfrom the surgical field of the patient. Nipple 14 may be connected to asource of negative pressure (VP) for creating a suction in the interior16 of sphere 12. This draws blood inwardly through nipples 30 and 32 andup the hollow interior 34 central column 36. From there the blood passesout the open end 40 of the column 36 and is spread in thin sheets overthe spreader plate 38, thereby removing some of the air bubbles whichmay have been entrapped in the blood. The blood then passes through thepolypropylene mesh mate rial 46 and the nylon bag 48 befor returning,being pumped or solely by the influence of gravity, through the outletnipple 42 to be sent, either directly or indirectly by tubing 60, backto a patient. Any air bubbles which escape from the blood as it passesover the plate 38 and then into the filter member 44 will be removedfrom the chamber 16 through the connection of the nipple 14 with thesource of negative pressure. Any solid particles in the blood will betrapped within the mesh 46 and retained therein while the bloodcontinuously passes through the mesh and down to the output nipple 42.

Preferably the filter means 44 is of such a size relative to theinterior 16 of the sphere 12 that the interior chamber 46 of the filtermeans 44 extends well above a Plane which bisects the sphere, generallyalong the line of flanges 12c and 12d. This is to accommodate relativelylarge amounts of blood while still retaining an air space above the toplevel of the expected blood pool. It is undesirable for bubbling tooccur outside the filter element 44 which might be the case if thefilter were so small that the normal amount of blood retained within thesphere normally covered the filter. This invention envisions theprovision of a chamber 61 and a filter chamber 46 of sufficient size soas to continually provide an air space within the filter chamber 46above the normal pool of blood which would be processed by thereservoir.

It is to be noted that no valving elements are interposed in the path ofblood travel or in the fitting for connection with the source ofnegative pressure. Continuous, even blood flow can be directly regulatedby the relative difference in pressure applied to the interior of thesphere. Blood may pass freely through the inlet and outlet passages, andin the intermediate stages of being spread over plate 38 and throughfilter element 44, with no possibility of contamination because of thelack of any contact with moving parts, valving elements or the like. Itis intended that the body 12 and inlet and outlet assembly would be madeof a suitable inexpensive plastic material such as that sold by theGeneral Electric Co., under the trademark Lexan, so that the apparatusof this invention could be made cheaply enough to be used only once andthen disposed of, rather than having to sterilize the same for repeateduse.

It is to be understood that in addition to the mode of operationdescribed, the cardiotomy reservoir of this invention could be operatedby means of ap lying a vacuum to nozzle 14 of sufiicient magnitude toremove the blood from the surgical field, with the blood being withdrawnfrom the reservoir by means of a well known roller pump interposed inthe tubing 60. Another alternative operating mode would be to utilize aroller pump with the inlet tubing 58 to pump blood to the reservoir andallow the blood to drain from the reservoir by gravity.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, for some modifications will be obvious to those skilled inthe art.

Iclai m:

1. A reservoir for the storage of blood during surgical procedures,comprising:

a blood collecting chamber having a hollow interior,

an upper portion and a lower portion;

a vent on the upper portion of the chamber;

a hollow inlet joined to the lower portion of the chamber and having agenerally upright column extending into the chamber interior foradmitting blood to said interior, with a blood spreading plate mountedon said column; and

blood conditioning means extending upwardly within the chamber includinga self-supporting bag like filter with a hollow pouch of anti-foammaterial within the filter, the filter and pouch affording a generallyhollow sub-chamber generally embracing the column below the bloodspreading plate and extending about and above the column and bloodspreading plate, said plate being located in the bottom portion of saidsub-chamber, the blood conditioning means occupying a substantialportion of the volume of the chamber so that the volume of the blood inthe chamber regulated by the amount intro duced through the inlet andwithdrawn from the outlet may occupy a substantial portion of theinterior of the chamber without covering the entire blood conditioningmeans.

2. The reservoir of claim 1 wherein the inlet is provided with pluralfittings for connecting the inlet with more than one source of incomingblood.

3. The reservoir of claim 1 wherein the blood spreading surface isplanar and lies slightly below the open end of the blood inlet.

4. The reservoir of claim 1 wherein the chamber is provided withinwardly projecting ribs adjacent to the blood outlets for providingfilter supports and intermediate blood return channels for the unimpededoutflow of blood.

5. The reservoir of claim 4 wherein the column is provided with anoutwardly extending filter support rib.

References Cited UNITED STATES PATENTS 2,934,067 4/1960 Calvin 1282l42,982,286 5/1961 Welch 128276 3,044,663 7/ 1962 Norton et al. 3,087,4904/1963 Broman 128214 3,175,555 3/1965 Ling 128-214 3,246,767 4/1966 Pallet al. 210--505 REUBEN FRIEDMAN, Primary Examiner T. A. GRANGER,Assistant Examiner U.S. Cl. X.R. 1282l4, 276

